Proc-GS: Procedural Building Generation for City Assembly with 3D Gaussians

Buildings are primary components of cities, often featuring repeated elements such as windows and doors. Traditional 3D building asset creation is labor-intensive and requires specialized skills to develop design rules. Recent generative models for building creation often overlook these patterns, leading to low visual fidelity and limited scalability. Drawing inspiration from procedural modeling techniques used in the gaming and visual effects industry, our method, Proc-GS, integrates procedural code into the 3D Gaussian Splatting (3D-GS) framework, leveraging their advantages in high-fidelity rendering and efficient asset management from both worlds. By manipulating procedural code, we can streamline this process and generate an infinite variety of buildings. This integration significantly reduces model size by utilizing shared foundational assets, enabling scalscalable generation with precise control over building assembly. We showcase the potential for expansive cityscape generation while maintaining high rendering fidelity and precise control on both real and synthetic cases. Project page: https://city-super.github.io/procgs/ Figure 1. Architectural structures in urban environments often exhibit repetitive patterns, such as the arrangement of windows and doors in buildings. Our approach focuses on extracting 3D base assets from predefined layouts and multi-view captures of buildings. Utilizing 3D-GS for reconstruction, we incorporate procedural code constraints during optimization to decompose the building entity into distinct 3D assets. (1) The top row illustrates two real-world building examples, showcasing their appearances before and after editing. (2) The bottom row demonstrates the scaled-up city-level assembly achieved using UE's City Sample assets. ProcGS not only facilitates geometry editing but also enables the generation of new buildings by modifying or defining new procedural rules, offering a flexible, efficient, and scalable framework for city assembly with high-fidelity and precise control.